That special feature of guinea pig seminal vesicle allowing separation of epithelium from underlying stromal tissue lends itself to the development of a homogeneous in vitro androgen-responsive cell system. The epithelial cells will be incubated in vitro with various androgens and estrogens and and then will be assayed for biochemical evidence of androgen action. The activities of ornithine decarboxlase, total nuclear phosphokinase, and RNA polymerases I and II, the cytosolic receptor binding of androgens and estrogens, fructogenesis and fructose secretion, the rate of synthesis of general intracellualr proteins, and the synthesis and secretion of four specific androgen-inducible soluble proteins will be quantitatively and chronologically analyzed. Short-term in vitro cultivation of intact epithelium and dispersed epithelial cells, longer term "organ culture" of intact seminal vesicle and separated epithelium, and multiple passaged cultures of epithelial and mixed epithelial and stromal cells will be investigated. Concurrently, nuclear acceptor binding of cytoplasmic androgen-receptor complexes will be studied in purified nuclei of seminal vesicle epithelium obtained from castrated and hormonally repleted animals. The acceptor binding sites in chromatin from purified nuclei will be identified as protein, nucleoprotein, or DNA using protein-dissociating systems, When the physiologic features of nuclear acceptor binding from seminal vesicles of intact animals are elucidated, and reliable acceptor binding assays are available, nuclear acceptor binding in the in vitro cell systems will be investigated and functionally related to the occurrence of other androgen specific biochemical eyents.